[mike sevel]

E93 79k miles. Now I have two opinions that my head gasket is leaking. Fix is very expensive especially around the Christmas bills season. Can you suggest
a temporary fix like a bead of silicone or other sealant that withstand the engine temperature?
Thanx,
Mikey

[Welcome to NBA Jam]

A quality temporary head gasket fix does not exist. Are you certain your head gasket is blown? It's generally a rare occurrence on BMWs.

[whyzee125]

Was it a BMW specific shop that diagnosed it? I don’t think I’ve ever heard of a blown head gasket on an e90. I bet your OFHG is leaking ans causing oil to get in your coolant?

There are sealants like blue devil that work pretty well but I wouldn’t use it in an engine you are going to fix or if there’s turbos in the mix. They work ok on old school simple engines where you can easily bypass the thermostat to do it. If it’s not overheating, I would just keep lots of water or coolant on hand til you can afford to properly fix it

[ctuna]

OFG and Valve cover leaks are almost guaranteed but actual
Head Gasket leaks are almost unheard of.

[oVeRdOsE.]

- If OFHG : change it asap, easy and cheap, like 15$.
- If valve cover : add more torque on the bolts, not recommended, but worked for me. (change the gasket cheap too, 35$ and 3h)
- If headgasket, well, this is a hard job, if you're sure, and you see the leak : brake cleaner + JB weld, the old recipe (higher pressure hold), harder to find, but they still exist.
You can try to torque the bolds, but will take time to get there, and if the torque is to high and broke something, very hard to use helicoil there.

[mainbearing]

Maybe the two headbolts popped loose?

https://www.pelicanparts.com/BMW/tec...lt_Testing.htm